1. CHEMICALS IN ACTION Thermal Decomposition Reactions

2. Learning objectives To know what is meant by a “thermal decomposition” To recognise what happens during the thermal decomposition of limestone Understand the thermal decomposition of limestone. Know how limestone is made

3. Thermal Decomposition Reactions A thermal decomposition occurs when a compound undergoes a reaction when it is heated. No other substance is involved in the reaction.

4. Thermal decomposition of copper carbonate If heated copper carbonate will undergo a thermal decomposition.

6. Thermal decomposition of copper carbonate The copper carbonate reacts when heated with no additional chemicals involved. CuCO 3(s) heat CuO (s) + CO 2(g)

7. Limestone Chemistry text p46

8. Uses of limestone

9. Thermal decomposition of limestone Carry out the practical outlined on the worksheet. If you do not heat the limestone long enough you will not get any of the expected results

11. Reactions you need to know by heart! Thermal decomposition of limestone (calcium carbonate) calcium carbonate calcium oxide + carbon dioxide CaCO 3(s) CaO (s) + CO 2(g) Calcium oxide + water calcium hydroxide CaO (s) + H 2 O (l) Ca(OH) 2(aq) Calcium hydroxide + carbon dioxide calcium carbonate + water Ca(OH) 2(aq) + CO 2(g) CaCO 3(s) + H 2 O (l)

12. Information on limestone and its products Read p48 of the Chemistry text. Make a set of bullet points on “The manufacture of calcium hydroxide – slaked lime”.

13. Learning objectives To know what is meant by a “thermal decomposition” To recognise what happens during the thermal decomposition of limestone Understand the thermal decomposition of limestone. Know how limestone is made